Downtown San Jose’s Climate and Emissions

Over the past few years, the city of San Jose has implemented many comprehensive policies in order to reach zero emissions by 2030. In analyzing the breakdown of vehicle and building emissions, the city can assess the effectiveness of programs such as Climate Smart San Jose and move towards the future with a clearer picture of what can be improved and who should be targeted to reduce emissions within the city. The following assesses vehicle and building (residential and commercial) CO2 emissions in Downtown San Jose (zip codes 95112 and 95113). Downtown San Jose is the source of a lot of commute and commercial activity and therefore emissions for the city. This is an important but also epistemologically difficult area to target who is responsible for reducing emissions.

Vehicle Emissions

Using LODES Data, this section will analyze the commutes to and from Downtown San Jose.

Routing

This map shows the routes using origin and destination points of Downtown San Jose (95112 & 95113) commutes.These commutes stretch all the way through California, but seem the most concentrated in the Bay Area.

#GHG Vehicle Emissions Using the California Air Resources Board (CARB) Emission Factors (EMFAC) model, we can examine the on road emissions rates (tons / year) for downtown San Jose by year.

Vehicle Category: EMFAC202x Categories, LDA (“Passenger Cars”) and LDT1 (“Light-Duty Trucks (GVWR <6000 lbs and ETW ≤3750 lbs)”) with the Fuel: Gasoline, Diesel, Electricity.

Plotting

This plot shows the Average Vehicle Emissions in Downtown San Jose from 2013 to 2019 using the EMFAC Data. From 2013, the Vehicle Emissions slowly rose with a slight decrease in 2019. It is also interesting that the City of San Jose adopted “Climate Smart San Jose,” a plan to address climate change and reduce emissions in 2018, a year before the slight decreases in vehicle emissions. The city is also promoting Electric Vehicles and highlighting incentive and rebate programs.

Building Emissions

Using PG&E Data we can assess the building emissions in Downtown San Jose from 2013 to 2019. This data includes both Electric in total kilowatt-hours (TOTALKWH) and Gas total therms (TOTALTHM) data from Residential and Commercial buildings. These metrics can be aggregated to assess total CO2 Emissions. Using these emissions factors, we can then complete the conversion to total CO2 emissions.

This plot shows the energy usage in Downtown San Jose buildings (95112 & 95113) from 2013 to 2019. Electricity usage seems to be significantly higher than Gas usage except in 2019 when Electricity usage goes down to a similar level to that of Gas. It is also interesting to note the stark rise of Electricity usage in 2017. The City of San Jose, as part of its Climate Smart San Jose initiative is highly promoting building electrification and decarbonization.

This stacked plot shows the breakdown of Energy usage types as compared with total emissions in Downtown San Jose as normalized with population and job count data. . It is encouraging to see the downward trend of overall emissions from 2013 to 2019. Examining 2019, but it seems like what has been the main factor decreasing is Commercial Electricity usage whereas the others remain pretty similar. It is especially interesting to note that Commercial Electric Usage almost disappears as compared to a sharp rise in Commercial Gas Usage. This is interesting given the city’s policies and pushes such as the “Switch is On” campaign towards building electrification and decarbonization. Vehicle Emissions remain at about the same levels in emissions across 2013 to 2019.

This stacked graph shows the proportions of emissions and their environmental impact in CO2-eq which measures the global warming potential. As seen in the last plot, the increase in Commercial Gas usage also has the highest proportional CO2-eq with the greatest potential to negatively impact the environment. The proportion of emissions is also seen to be slightly going up, over the years. Perhaps this is due to growing industry and commuting in and to Downtown San Jose. These are factors that the city should take into account in order to ensure the success of their thoughtful plans to reduce emissions and become carbon neutral by 2030.

Total Annual Greenhouse Gas (GHG) Emissions

#Annual GHG Emissions Per Trip Over time (2013 to 2019), we can see the Average Annual Vehicle Emissions increase in terms of commutes (besides a slight decrease in 2014). This seems to work against many of the goals set by the city in promoting EV usage and decreasing vehicle emissions. Perhaps this is due to the increasing number of companies turning to downtown San Jose (such as Google and Amazon) as locations of expansion, bringing their commute emissions with them.

Zooming in to the trend line, we can see that emissions have gone up over time but 2018 to 2019 sees a downward trend. Perhaps this decrease is due to policies such as Climate Smart San Jose. It will be important to track these changes along with changes in resident v. commuter demographic data as the city identifies the most effective targets for electrification.

Heating and Cooling Degree Days

Using the Cal-Adapt Degree Day tool we can collect Heating Degree Day (HDD) and Cooling Degree Day (CDD) Data. These measures estimate the energy used to cool and heat buildings. A CDD is a day in which the temperature exceeds a base of about 65*F (below which AC or cooling is not needed). A HDD is the inverse.

This is a graph of residential gas (KBTU/resident/HDD), residential electricity (KBTU/resident/CDD), commercial gas (KBTU/job/HDD), and commercial electricity (KBTU/job/CDD) over time.

This data shows that the Energy Use for Cooling Degree Days for jobs/commercial in Downtown San Jose have always been higher across 2013 to 2019, followed by residents on CDDs, then residents on Heating Degree Days, and finally jobs/ commercial usage on HDDs (with little overlap). Notably, the commercial energy usage on CDDs seems to fluctuate over the years with a noticeable dip from 2017 to 2018, plateauing from there. This is interesting, that despite rising temperatures and heat waves, the CDD energy usage is going down.

Conclusion

Overall, the City of San Jose should take into account the emissions trends in Downtown San Jose when assessing the effectiveness of their climate initiatives across the city. City planning, industrial expansion, commutes, and equity concerns should all be considered in future implementation of policies, especailly as they apply to non-residents and commercial energy usage which is a the largest portion of Downtown San Jose’s Emissions.